全文获取类型
收费全文 | 7562篇 |
免费 | 68篇 |
国内免费 | 55篇 |
专业分类
安全科学 | 202篇 |
废物处理 | 396篇 |
环保管理 | 595篇 |
综合类 | 1174篇 |
基础理论 | 1731篇 |
环境理论 | 9篇 |
污染及防治 | 2477篇 |
评价与监测 | 624篇 |
社会与环境 | 446篇 |
灾害及防治 | 31篇 |
出版年
2023年 | 89篇 |
2022年 | 205篇 |
2021年 | 229篇 |
2020年 | 117篇 |
2019年 | 125篇 |
2018年 | 261篇 |
2017年 | 281篇 |
2016年 | 382篇 |
2015年 | 262篇 |
2014年 | 404篇 |
2013年 | 661篇 |
2012年 | 458篇 |
2011年 | 511篇 |
2010年 | 342篇 |
2009年 | 299篇 |
2008年 | 464篇 |
2007年 | 414篇 |
2006年 | 377篇 |
2005年 | 289篇 |
2004年 | 251篇 |
2003年 | 192篇 |
2002年 | 168篇 |
2001年 | 102篇 |
2000年 | 51篇 |
1999年 | 61篇 |
1998年 | 35篇 |
1997年 | 28篇 |
1996年 | 30篇 |
1995年 | 41篇 |
1994年 | 39篇 |
1993年 | 14篇 |
1992年 | 23篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 17篇 |
1988年 | 20篇 |
1987年 | 13篇 |
1986年 | 29篇 |
1985年 | 16篇 |
1984年 | 14篇 |
1983年 | 15篇 |
1982年 | 19篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1972年 | 10篇 |
1966年 | 19篇 |
1965年 | 11篇 |
1958年 | 11篇 |
1956年 | 12篇 |
排序方式: 共有7685条查询结果,搜索用时 15 毫秒
981.
982.
Alejandra V. González Valeria Gómez-Silva María José Ramírez Francisco E. Fontúrbel 《Conservation biology》2020,34(3):711-720
Genetic diversity is a key factor for population survival and evolution. However, anthropogenic habitat disturbance can erode it, making populations more prone to extinction. Aiming to assess the global effects of habitat disturbance on plant genetic variation, we conducted a meta-analysis based on 92 case studies obtained from published literature. We compared the effects of habitat fragmentation and degradation on plant allelic richness and gene diversity (equivalent to expected heterozygosity) and tested whether such changes are sensitive to different life-forms, life spans, mating systems, and commonness. Anthropogenic disturbance had a negative effect on allelic richness, but not on gene diversity. Habitat fragmentation had a negative effect on genetic variation, whereas habitat degradation had no effect. When we examined the individual effects in fragmented habitats, allelic richness and gene diversity decreased, but this decrease was strongly dependent on certain plant traits. Specifically, common long-lived trees and self-incompatible species were more susceptible to allelic richness loss. Conversely, gene diversity decreased in common short-lived species (herbs) with self-compatible reproduction. In a wider geographical context, tropical plant communities were more sensitive to allelic richness loss, whereas temperate plant communities were more sensitive to gene diversity loss. Our synthesis showed complex responses to habitat disturbance among plant species. In many cases, the absence of effects could be the result of the time elapsed since the disturbance event or reproductive systems favoring self-pollination, but attention must be paid to those plant species that are more susceptible to losing genetic diversity, and appropriate conservation should be actions taken. 相似文献
983.
Fabio Granados-Chinchilla María de Jesús Arias-Andrés María Laura Fernández Montes de Oca 《Journal of environmental science and health. Part. B》2020,55(2):127-134
AbstractMonensin (MON) is a coccidiostat used as a growth promoter that can reach the environment through fertilization with manure from farm animals. To verify whether field-relevant concentrations of this drug negatively influence the structure and activity of tropical soil bacteria, plate counts, CO2 efflux measurements, phospholipid fatty acids (PLFA) and community-level physiological profiling (CLPP) profiles were obtained for soil microcosms exposed to 1 or 10?mg kg?1 of MON across 11?days. Although 53% (1?mg kg?1) to 40% (10?mg kg?1) of the MON concentrations added to the microcosms dissipated within 5?days, a subtle concentration-dependent decrease in the number of culturable bacteria (<1 log CFU g?1), reduced (?20 to ?30%) or exacerbated (+25%) soil CO2 effluxes, a marked shift of non-bacterial fatty acids, and altered respiration of amines (1.22-fold decrease) and polymers (1.70-fold increase) were noted in some of the treatments. These results suggest that MON quickly killed some microorganisms and that the surviving populations were selected and metabolically stimulated. Consequently, MON should be monitored in agronomic and environmental systems as part of One Health efforts. 相似文献
984.
Péter Török 《Conservation biology》2018,32(1):249-250
985.
Guerrero Hernandez Alejandro Sallyth de Arruda Lúcia Valéria Ramos 《Environment, Development and Sustainability》2021,23(9):12842-12866
Environment, Development and Sustainability - A developing country that does not have adequate energy solutions in non-interconnected zones (ZNIs) undoubtedly experiences adverse effects in terms... 相似文献
986.
Amanda Xuereb Cassidy C. D'Aloia Marco Andrello Louis Bernatchez Marie-Josée Fortin 《Conservation biology》2021,35(3):909-920
The availability of genomic data for an increasing number of species makes it possible to incorporate evolutionary processes into conservation plans. Recent studies show how genetic data can inform spatial conservation prioritization (SCP), but they focus on metrics of diversity and distinctness derived primarily from neutral genetic data sets. Identifying adaptive genetic markers can provide important information regarding the capacity for populations to adapt to environmental change. Yet, the effect of including metrics based on adaptive genomic data into SCP in comparison to more widely used neutral genetic metrics has not been explored. We used existing genomic data on a commercially exploited species, the giant California sea cucumber (Parastichopus californicus), to perform SCP for the coastal region of British Columbia (BC), Canada. Using a RAD-seq data set for 717 P. californicus individuals across 24 sampling locations, we identified putatively adaptive (i.e., candidate) single nucleotide polymorphisms (SNPs) based on genotype–environment associations with seafloor temperature. We calculated various metrics for both neutral and candidate SNPs and compared SCP outcomes with independent metrics and combinations of metrics. Priority areas varied depending on whether neutral or candidate SNPs were used and on the specific metric used. For example, targeting sites with a high frequency of warm-temperature-associated alleles to support persistence under future warming prioritized areas in the southern coastal region. In contrast, targeting sites with high expected heterozygosity at candidate loci to support persistence under future environmental uncertainty prioritized areas in the north. When combining metrics, all scenarios generated intermediate solutions, protecting sites that span latitudinal and thermal gradients. Our results demonstrate that distinguishing between neutral and adaptive markers can affect conservation solutions and emphasize the importance of defining objectives when choosing among various genomic metrics for SCP. 相似文献
987.
Hani R. El Bizri Thaís Q. Morcatty João Valsecchi Pedro Mayor Jéssica E. S. Ribeiro Carlos F. A. Vasconcelos Neto Jéssica S. Oliveira Keilla M. Furtado Urânia C. Ferreira Carlos F. S. Miranda Ciclene H. Silva Valdinei L. Lopes Gerson P. Lopes Caio C. F. Florindo Romerson C. Chagas Vincent Nijman Julia E. Fa 《Conservation biology》2020,34(2):438-448
The switch from hunting wild meat for home consumption to supplying more lucrative city markets in Amazonia can adversely affect some game species. Despite this, information on the amounts of wild meat eaten in Amazonian cities is still limited. We estimated wild meat consumption rates in 5 cities in the State of Amazonas in Brazil through 1046 door-to-door household interviews conducted from 2004 to 2012. With these data, we modeled the relationship between wild meat use and a selection of socioeconomic indices. We then scaled up our model to determine the amounts of wild meat likely to be consumed annually in the 62 urban centers in central Amazonia. A total of 80.3% of all interviewees reported consuming wild meat during an average of 29.3 (CI 11.6) days per year. Most wild meat was reported as bought in local markets (80.1%) or hunted by a family member (14.9%). Twenty-one taxa were cited as consumed, mostly mammals (71.6%), followed by reptiles (23.2%) and then birds (5.2%). The declared frequency of wild meat consumption was positively correlated with the proportion of rural population as well as with the per capita gross domestic product of the municipality (administrative divisions) where the cities were seated. We estimated that as much as 10,691 t of wild meat might be consumed annually in the 62 urban centers within central Amazonia, the equivalent of 6.49 kg per person per year. In monetary terms, this amounts to US$21.72 per person per year or US$35.1 million overall, the latter figure is comparable to fish and timber production in the region. Given this magnitude of wild meat trade in central Amazonia, it is fundamental to integrate this activity into the formal economy and actively develop policies that allow the trade of more resilient taxa and restrict trade in species sensitive to hunting. 相似文献
988.
989.
990.